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sciencehabit writes "Anyone watching the autumn sky knows that migrating birds fly in a V formation, but scientists have long debated why. A new study of ibises — where researchers took to microlight planes and recorded birds strapped with GPS in-flight — finds that these big-winged birds carefully position their wingtips and sync their flapping, presumably to catch the preceding bird's updraft and save energy during flight."

HEY HEY GUYS!!! I just discovered this great thing, when an apple falls from a tree and lands on the ground there must be some sort of force doing it! I think I'll call it fallivity. Yeah! And if you notice everything pulled down by fallivity falls at the same speed! 9.81 m/s^2 by my calculations!

And if the guy had claimed it was first discovered in the 80s that would be a point, but all he claimed was was told about it as a child in the 80s. Which would put the discovery date way before then as an upper bound since school teachers aren't really renowned for keeping up on scientific research in areas other than how to bore children. And not offer any lower bound as all since teachers also tell their students things like "grass needs water to live" which I'm pretty sure isn't a recent discovery.

which was done decades ago, I laughed at the 80s mention, I was taught as child in the 60s and in 70s this was popular science fair homemade wind tunnel experiment.

About once a month slashdot runs article on "discovery" or "invention" that is decades old

Really? They performed experiments with syncronised flapping wings in a homemade wind tunnel? They actually timed real birds wing flapping to confirm the hypothesis? I call bullshit on this one. It is very typically Slashdot "stupid science / is this new??" kneejerk reaction and as usual there is no fucking evidence. I suspect the experiments you are talking about was with fixed wings.

In any case, aerodynamics with fixed wings is obviously pretty ancient by now, but sensible modelling of flapping wings is f

I was taught as child in the 60s and in 70s this was popular science fair homemade wind tunnel experiment.

Did these science-fair experiments demonstrate the specific contribution of synchronized flapping? Even if they did, this claims to be the first experiment to show that birds flap synchronously with sufficient precision to benefit from it.

point is you don't even need synchronized flapping to have benefit in a V formation, the reason for the V formation is not to have syncronized flapping, it's just an additional benefit

Have you ever been in a discussion where some Dunning-Kruger type tries to make a big deal over something that everyone else knows perfectly well, and who has failed to notice that the discussion has gone beyond that point? That's the role that you are playing here, as are the AC who started this thread and everyone who thought it was insightful.

The point of the study, and the thing that makes it newsworthy, is that it demonstrates that birds are capable of extracting energy from the unsteady flow created b

Here here! And it's even worse! This bullshit about the higgs boson at CERN last year! WE KNEW IT IN 1964!!! 40 YEARS OLD NEWS!!! (/s)

Hypotheses need to be tested, experiments need to be repeated, ideally with increasing certainty. You absolutely were not stuffing ibises into wind tunnels in science fairs. It would have been more interesting had they gotten a negative result, as was true with the higgs boson, but a positive result confirming your old hypotheses is still important science.

The BBC would report on the link between sex and pregnancy if they had the chance. You try filling that many hours day after day with news and you'll end up reporting anything that happens, whether it's newsworthy or not.

I wasn't thinking of that, but you raise a good point. Since scientific drug testing works so well in the Tour de France, why should birds be exempt from it? That's only fair to the birds' fans and sponsors - and most of all - to the other birds.

I think this applies more to larger birds that fly long distances in a flock. The energy savings could make a significant difference for them. I don't see small birds flying in a V formation that much.

Pigeons fly in V formation, as do crows. Actually, most birds that size do. Once you start getting smaller though, they flock, but don't do the V formation -- even with migratory birds. Once you're down to Juncos, Chickadees and Sparrows, they use more of a chaotic swarm and weave method to confuse predators -- but they also tend to hop from tree to tree, and don't fly long distances in the open.

What really confuses me is seagulls -- they flock like smaller birds and yet travel distances and have few (la

This was my first reaction too. However, reading the article (I know, I must be new here) clears it up,

There are two reasons birds might fly in a V formation: It may make flight easier, or they’re simply following the leader. Squadrons of planes can save fuel by flying in a V formation, and many scientists suspect that migrating birds do the same. Models that treated flapping birds like fixed-wing airplanes estimate that they save energy by drafting off each other, but currents created by airplanes are far more stable than the oscillating eddies coming off of a bird. “Air gets pretty darn wiggy behind a flapping wing,” says James Usherwood, a locomotor biomechanist at the Royal Veterinary College at the University of London in Hatfield, where the research took place.

Just as aerodynamic estimates would predict, the birds positioned themselves to fly just behind and to the side of the bird in front, timing their wing beats to catch the uplifting eddies. When a bird flew directly behind another, the timing of the flapping reversed so that it could minimize the effects of the downdraft coming off the back of the bird’s body.

“From a behavioral perspective it’s really a breakthrough,” says David Lentink, a mechanical engineer at Stanford University in Palo Alto, California, who was not involved in the work. “Showing that birds care about syncing their wing beats is definitely an important insight that we didn’t have before.”

And from the actual research article,

Many species travel in highly organized groups. The most quoted function of these configurations is to reduce energy expenditure and enhance locomotor performance of individuals in the assemblage. The distinctive V formation of bird flocks has long intrigued researchers and continues to attract both scientific and popular attention. The well-held belief is that such aggregations give an energetic benefit for those birds that are flying behind and to one side of another bird through using the regions of upwash generated by the wings of the preceding bird, although a definitive account of the aerodynamic implications of these formations has remained elusive.

We conclude that the intricate mechanisms involved in V formation flight indicate awareness of the spatial wake structures of nearby flock-mates, and remarkable ability either to sense or predict it. We suggest that birds in V formation have phasing strategies to cope with the dynamic wakes produced by flapping wings.

So, it's a little bit of a behavioral science study...is saving energy why they do it, or is saving energy just a happy consequence? And it's also a bit of a mechanism study...to gain the most aerodynamic benefit requires adjustment of the wing and position to meet the updrafts, so how well do the birds do this?

Yes.
And similar behaviors have been successfully "discovered" by genetic algorithms run by computer simulations.

Maybe some/.er will share examples here or even find such an experiment for the V flight.
At least I remember a successful simulation for obstacle avoidance behaviour with V flight, which is even better actually (science French mag about emergence)

>So, it's a little bit of a behavioral science study...is saving energy why they do it, or is saving energy just a happy consequence?

That seems like a question that would be *extremely* hard to answer in any way except "of course they do it because it saves energy". Assume for the sake of argument that it can somehow be proven that each individual bird flies as it does simply because it "feels good", or any other reason. The question still remains *why* does it "feel good", with the answer almost certainly being that evolution, that old non-sentient intelligence, sculpted the species in favor of some random mutation that made a more energy-efficient behavior "feel good". If there hadn't been a survival benefit to the behavior then it's unlikely it would have spread throughout the entire population.

It's like the adage says: "We don't like sugar because it's sweet, sugar is sweet because we like it". There's nothing inherently "sweet" about a sugar molecule, sweetness is a function of our brains interpretation of the signals from the chemo-receptors on our tongues. Sugar triggers a pleasure-response (sweetness) because our metabolisms can harness it as a rich energy source. Some distant ancestor who found sugar pleasurable consumed more energy rich fruits, and thus had more energy available and could out-compete their "sweet-less" rivals, and so the mutation spread throughout the population. Cats on the other hand are obligate carnivores whose metabolisms can't efficiently process sugars, and they lack the appropriate chemoreceptors to detect them - for them sugar is *not* sweet, and any mutation that changed that would rapidly fall out of the population because it would reduce the amount of fats and proteins consumed in favor of sugars that don't provide them much energy, making the afflicted individuals less competitive.

Research into the actual *mechanism* of the energy savings is still interesting though, we are only just beginning to understand the subtleties of flexible-wing flight. Dragonflies for example actually appear to use their front wings specifically to generate vortices (generally considered energy-sapping flaws to be minimized in fixed-wing aircraft) rather than producing thrust - the rear wings then interact with those vortices in a manner that provides more thrust than they could hope to generate directly. *Extremely* sophisticated energy-optimizing behavior that makes our fanciest aerodynamics technologies look like dog-paddling in comparison.

Maybe, although it also makes sense explaining it from the individual agent perspective. If I'm driving over a long segmented bridge, then every time I hit a new segment, it causes my car to bounce slightly. If I'm driving at the 'wrong' speed the end of my bounce coincides with the next segment dip, meaning my bounces get increasingly worse. So I slow down a bit to avoid this effect. If I'm a bird, and I'm flying behind and to the left of another bird, and every time my own wings aren't providing lift happ

Seriously dudes, its much simpler than that.Birds fly in a 'V' formation because they "poop in flight". Unless you want to be covered in excrement you learn to fly a little offset from the bird in front of you so that you don't get smeared with the "exhaust". Makes it really hard to see where you're flying. Even birds can figure that much out.

Actually, no. You weren't taught that birds use synchronous wing-flaps to minimize the drag. You were taught that the V-formation of birds saves energy. But until now it seems that while for planes with fixed wings, where the air flow around the wing of the plane in front is still laminary enough to provide lift, it wasn't clear how this works with birds, whose wings cause the air to become turbulent. Now it could be observed that the synchronous wing-flap with shifting the flapping half a cycle from bird t

That would presumably include how to dissolve a corpse in acid and how to make a military-grade flamethrower, which I'm fairly sure would violate some sort of FCC regulation. Even if it didn't, it's a family show, and has to pitch its content accordingly.

I've seen this comment suggested as the most important part of any scientific article.;-)

Actually, I like to mention this to the folks on the religious side of the religion-vs-science "war". If you think about it, saying "further research is needed" is a clear, unambiguous statement that the writer doesn't know and understand everything about the topic at hand. This is a sign that the writer probably is actually a scientist.

Religious people, OTOH, already know everything there is to know about whate

This has long been the explanation of why birds fly in an echelon formation and why throughout a migration the front ranks cycle from the front to the rear. As the leading rank of birds tire, the next rank takes over allowing them a bit of a rest.

Damn it slashdot, read the article. Although it doesn't claim explicitly that this is the first time this hypothesis has been tested, if anything, it appears this was just a study that verified that this hypothesis is correct. People already posited this and apply it for jets (see jets that fly in echelon formation), but, at least what is said and implied in TFA, this seems to still be something that is a matter of debate.

Tailgating is dangerous. But if you drive in the adjacent lane on a highway next to another car, you can gain higher MPG if you're trailing behind at an angle. Essentially in the blind-spot of the other driver. It's still dangerous, just be sure to break loose on those long interstate drives to reminding the other driver you're still nearby. Have a newer car that displays the MPG in real time? The change is rather impressive once you find that o

Incorrect. Watch some windtunnel tests. The vortex is behind the vehicle, not beside it.

A better word for this is "slipstream". You get close enough to have no air to push through. If your car has radar cruise control, following close enough to make a huge difference isn't too dangerous. (obviously on a highway where people aren't very unpredictable. and you're far better off following semi's.)

Exactly. I once had a colleague who, when on the highway, ALWAYS hung behind a truck. He had impressively low MPG - and needed much more time than others to reach his target, but simply calculated this in. I have verified it myself with a Renault Laguna: hanging behind a truck can reduce your MPG up to 40%.

I'm assuming the parent is European (Renault Laguna) and we tend to talk about fuel-efficiency in liter per 100 km. Hence, a lower number actually means better efficiency in that context, hence the confusion.

FYI: My dashboard allows for these 3 options: MPG, l/100Km, Km/l. I actually like the km/l as it is much more interesting and also has better 'scaling', but sadly the l/100Km is most widely used in that respect that I'm pretty sure that if I would say I got 20km/l on a given trip I'd probably meet blank

I accept that in modern common parlance, "exponentially" just means "grows significantly compared to the increase in its input". Your use fitted that.However, when the media say things like (and this is *purely* illustrative, not a quote) "Support for the UKIP increased exponentially when Alex Wood stepped down from office, and apologised for his Nazi salute on facebook", then I get all smack-them-in-the-face-with-a-baseball-bat-that's-got-rusty-screws-sticking-out-of-it, and for good reason. Before vs. aft

I did not use the word "exponentially". And if and when I use it, I use it correctly, in the sense of "if input is n, then output grows as k^(C*n + D ), with k > 1. For "decimating", there actually is an accepted meaning of "reduce greatly in numbers", not only "reduce by a factor 10". I can look that up in the OED.

Actually no, vortices and slipstreams are two related but very distinct concepts. Slipstreaming or drafting involves taking advantage of reduction in aerodynamic drag available from traveling within someone else's the slipstream or "wind shadow" - the region directly behind them where the fluid is moving at approximately the same speed as the object itself. Vortex surfing is a related phenomena, but rather than traveling within someone's slipstream to reduce your air speed and thus drag at the same ground

It's almost as though theorists saying something is so isn't enough to convince engineers and experimentalists. This clear breach of the scientific method, where whatever theorists say must be so and experimentalists have to live with it whatever they mesure, has gone unpunished. Until this study we didn't know that this is why birds do this. Even after this study we don't know if this is why birds do this (the energetics could be a co-incidence). You sir, are an insufficiently skeptical moron.

Except that this isn't the first time the theory has been put to a test. If I'm not mistaken explicit experiments pertaining to this date back nearly half a century. Whether wittingly or not the echelon formation has been in application by the military for the same reasons hypothesized for far longer than that.

My wife and I were wondering the other day how the flock determined who was going to be out front. We also wondered about them trading positions, which we haven't observed, but if there's cycling through the ranks that part is answered, I guess.

In the northern hemisphere they actually fly in an A formation. Only in the southern hemisphere do they fly in a V.

Wouldn't that depend on whether they're flying north or south? I guess if they're flying west in the northern hemisphere they must be flying in a "less than" formation and east in a "greater than" formation then.

Although this may not be the first time the airflow effects have been measured "in the wild", I cannot remember any previous instance.

There are a lot of things "everybody knows" that have never been verified. It doesn't hurt to run the experiments and perform the verification.

"Everybody knew" that time passed slower on a body moving faster; after all, Einstain had said so. Still, it wasn't until we put sufficiently accurate chronometers on spacecraft that we really knew it, because they did, in fact, show that the spacecraft experienced less time than the ground stations. Although surface installations are "orbiting" at about 1000 MPH (too easy with a 24 hour day and 24000 mile circumference), and are at the 1G level of the Earth's gravity well (also has an effect), the space craft are moving at about 16000 MPH (90 minute orbit at 100 mile AGL) and still at nearly the 1G level of the gravity well. That 15000 MPH difference shows up readily, even after the adjustment for gravity.

Not birds, but I do recall a Mythbusters episode where they tried it with small aircraft and found a similar effect. Must have been a quite scary experiment:-) And as others pointed out, many wind tunnel experiments showed the same effects as well.

The point of the article is that the wake left by a flapping wing is more complicated than the wake left by a fixed wing such as an aircraft. It turns out (and I don't remember reading about this before) that the birds are actually adjusting their position and flapping to get the most benefit.

This makes sense logically, but this is the only study I know of that actually verified it. You know, like science requires...

You want to fly with your buddies. Do you form:
- everyone in line a single long line one behind the other? No because then all you can do is see is the person ahead of you and you are constantly surprised by their sudden accelerations (+ or -'ve) and you'd find yourself flying way slow and then way fast to catch up... like cars in traffic.- everyone line abreast i.e. beside each other stretching out to either side? No because then you have to keep looking from one side to the other trying to keep your distance from the next person and the same speed as them who are trying to keep speed with you so everyone ends up kind of rushing ahead then slowing down especially 'cause you can't see the partner two individuals away.OR- a vee formation where everyone gets behind and a little to the left or right of someone else? Yes. A leader will emerge if not already defined by the flock/squadron as top alpha creature/plane end everyone can easily see the individual in front to adjust to their speed and position, everyone can see approaching obstacles (in which case they can anticipate the movement of the individual they're following), and everyone can relatively easily take a quick look at the individuals all around them... an excellent formation for creatures or aircraft flying together and trying to avoid collisions...AND _THEN_.... distances get adjusted to maximize flight efficiency.

See how that works? Formation shape for safety from collision and then distances adjusted for flight efficiency.It's why aircraft fly in such formations... and it's why birds do it. Oh, and wolves, small herds, orcas, etc. Kind of anything travelling close with purpose.. even schools of fish are composed of a fractal pattern of 'v' formations ie. if not in front of everyone, the individual fish will get behind of, and to the side of the fish ahead of them... if they didn't we would see fish CUBES instead of fish BALLS

Honestly, formations based on aerodynamics?! It's a flock of ibises, Jim, not rocket scientists!

This illustrates the state of modern science. There is/was no debate: it is clear that evolution will reward mechanical efficiency, like it always does. Pelaton cyclists take turns at the front and draft each other, and you need only compare a road-race to a time-trial to see the efficiency gain (look at the length of the race, and how few small breakaways succeed). Bird's V-formations allow the same efficiency gain, and an evolution process too stupid to learn this and take advantage woul

If you actually examine it and it's creation process a beaver dam or termite mound is actually a pretty impressive feat of engineering possessing many functional details at least as impressive as anything found in most human dwellings. Passive environmental regulation systems. Near-optimal structural layout based on environmental factors. And in the case of ants at least this is accomplished with near-zero cognitive problem solving abilities.

But what is the advantage to flying in formation rather than in the disorganized flock that most short-range birds seem to prefer? These aren't bureaucratic minds pursuing order for the sake of order - instinctual behaviors almost always exist because they bestow a definite advantage upon those who display them. Or at least they did at some point in the past, and don't carry enough of a cost to have been bred away since the historical conditions changed

I know it was the accepted theory as long as I've been aware of it, but how many experiments have actually been done to confirm that the theory does in fact describe reality? Without experimentation to attempt to disprove your theories there's precious little difference between science and philosophy. Even if several independently corroborating experiments were done early on, it may still be worth revisiting the question them from time to time - both to discover new details hidden to old technology, and t

Ah, yes. "God did it" is always the naively simplest answer, but it rests on the premise that an incredibly powerful being is actively and consistently controlling the world. The existence of such a being is hardly a simple premise to accept - a mind is one of the most complex things we've discovered, presuming such a thing arose or always existed uncreated is hardly a simple premise, and the power and attention required for God to do everything personally in a consistent manner boggles the mind.

While I certainly won't deny a certain... aristocratic quality to cat behavior, I think it's also important to recognize that along with many similarities their are certain aspects of feline nature which are fundamentally alien to us, and that ascribing human motives to their behaviors is thus pretty much guaranteed to be wildly inaccurate on a regular basis. Come to think of it there are certain similarities to intersex communication - men